Manufacture of dyestuffs containing chromium



Patented Feb. 9, 1932 UNITED STATES PATENT OFFICE HANS KKMMERER, 0F MANNHEIM, AND KARL HOLZACH, OF LUDWIGSHAFEN-ON-THE- RHINE, GERMANY, ASSIGNDBS 'IO GENERAL .ANILINE WORKS, IN C., OF NEW YORK,

N. Y., A CORPORATION 01? DELAWARE MANUFACTURE 01E DYESTUFFS CONTAINING GHR/OMIUM No drawing. Application filed July 24, 1926, Serial No. 124,776, and in Germany August 6, 1925.

Various processes for the nianutacture of dyestuffs containing chromium and having valuable properties are known, for example those described in the U. S. Patents 1,090,123, 1,261,601 and others.

lVe have now found that the manufacture of such dyestuffs can be carried out with particular advantage by acting with a chromium compound on a dyestutf capable of being chromed at an elevated temperature at which no decomposition of the dyestutt occurs and under pressure. Thereby the time of heating necessary for the -formation of the chromium compounds of the dyestuiis is considerably reduced. In the claims as hereunto appended the term naphthol is used in a broad sense including also naphthols containing other substituents and in particular sulfonic acid groups.

it is often advantageous to subject the dyestufi's containing chromium so obtained to a subsequent treatment with alkaline agents in the manner described in the German Patent 4519825.

lhe following examples will further illustrate how our invention may be carried out in practice, but the invention is not limited to these examples. The parts are by weight.

Ewample J 100 parts of the azo dyestufi obtainable from diazotized .l-amino-2-naphthol- 1-sultonic acid and beta-naphthol, 60 parts of -hron1ium formate containing about 30 per cent of CI'gOg and. 1000 parts of water are heated for 2 hours to 105 C. in an autoclave. The d yestuil containing chromium is precipitated bf an addition of common salt and sucked oti'. whereupon the resulting paste is boiled with caustic soda lye of 4 Be. The solution is filtered, the soda lye is partly neutralized by means of hydrochloric acid, saturated with common salt and the precipitate is sucked 01f. The dyestutf so obtained dyes wool pure blue shades of very good fastness.

Example Q 100 parts of chromoxane blue R (see Schultz, Farbstoili'tabellen, 5th edition, page 379) are heated in an autoclave for an hour to 120 C. with 400 parts of a chromium formate solution containing 5 per cent 01? C150 whereupon the solution is evaporated to dry n-ess. The blue dyestuflf so obtained can be fixed on fibres in the manner described in the British Patents 7892 and 26460 of 1912 or when made into a color lake in the usual manner it may be used for example as a paste color for wall-papers.

E sample 3 100 parts of the dyestuli obtainable from diazotized tnitro- -amino-phenol and 2- phenylamino-8-naphthol-6-su1fonic acid are rented in an autoclave for 2 hours to 110 C. with an alkaline chromium glycerol solution prepared according to Example 1 of the German Patent 366,095 and containing 17 parts of C150 The resulting dyestuff is sucked oil and dried. It dyes wool dark brown shades of excellent fastness.

We claim:

1. In the production of chromium com pounds of o-hydroXy-azo dyestufi's obtainable from an o-hydroxy-diazo compound with a napthol, the step which comprises heating an o-hydroxy azo-dyest-uii of the said kind with a chromium compound ca pable of reacting therewith, in a closed vessel at a temperature sufficiently above 100 C. to produce superatmospheric pressure, but be low the temperature at which the dyestuif is destroyed.

2. In the production of chromium compounds of o-hydroXy-azo dyestuffs obtainable from an o-hydroxy-diazo compound with a naphthol, the step which comprises heating an o-hydroxyazo dyestufl" of the said kind with a chromium compound capable of reacting therewith, in a closed vessel at a temperature between 105 and 120 C.

3. The process of producing a chromiferous o-hydroXy-azo dyestufi' which comprises heating the o-hydroxy-azo dyestufl obtainable from diazotized 1-amino-2-naphthol-tsulphonic acid and beta-naphthol with a chromirun formate solution in a closed ves sel at 105 C.

4-. The process of producing a chromiferous o-hydroXy-azo dyestulf which comprises HANS KZ XMMERERQ m KARL HOLZACH. 

